Traffic controlling apparatus



April 18, 1939. P. P. STOKER TRAFFIC CONTROLLING APPARATUS Filed May 21935 4 Sheets-Sheet l @QNNN b win 6% eww SQ y 1 if??? E g @T NE L p NAN7 aw 6$ m e E5 k 114M] H H 8L 5km NNRN Nlw NNE N N wm wS N m6 zgfiw. m2.U a l w w P m u Qfiwmfi U \Al EN m QQNW Ewm Q 7 11% BMW 3 v vi 1 k TI5% v N v E HIS ATTORNEY Filed May 2, 1955 4 Sheets-Sheet 2 &

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ml E T BY 622W HIS ATTORNEY April 18, 1939. P. P. STOKER TRAFFI C CONTROLLING APPARATUS 4 Sheets-Sheet 3 Filed May 2, 1935 April 18, 1939.P. P. STOKER TRAFFIC CONTROLLING APPARATUS Filed May 2, 1955 4Sheets-Sheet 4 INVENTOR Paul PSfOAQP BY Q/Z'W HIS ATTORNEY Patented Apr.18, 1939 UNITED STATES PATENT OFFICE TRAFFIC CONTROLLING APPARATUSApplication May 2, 1935, Serial No. 19,462

16 Claims.

My invention relates to railway traffic controlling apparatus, and moreespecially to that class of apparatus wherein an operator located at acentral dispatching office, or operators located at the respective endsof a controlled stretch of track, direct traffic through the stretch.

An object of the invention is to provide a trafiic locking circuit thatcontrols the intermediate signals of the stretch and consists of but twoconductors extending between the ends of the stretch and two additionalconductors extending between adjacent signal locations of the stretch.Another object is to so arrange the circuits and apparatus that trafficmay be set up in either or both directions from an intermediate point inthe stretch.

I will describe one form of apparatus embodying my invention and willthen point out the novel features thereof in claims.

The accompanying drawings, Figs. 1 to 4, inclusive, when placedend-to-end from left to right in the order named, show a diagrammaticview of one form of the apparatus embodying my invention as applied to astretch of single track from a passing siding Pl shown at the left-handend of the stretch, to a passing siding P3 shown at the right-hand endof the stretch. By means of the customary insulated rail joints thetraffic rails of the stretch are divided up into track sections B4T, IT,AZT, B2'I, IUT, AIOT, BHIT, I2T, AIZT, ST, and AGT with only thelefthand end of the section A4T shown. The sections IT and ST includeswitches 3.3 IS and 35, respectively, of the associated sidings PI andP3, while one of the intermediate sections IDT includes a switch 28 forthe associated siding P2. It is to be understood, however, that theinvention is not confined to this 40 particular arrangement of tracksections and this arrangement is only one of many convenient ways ofdividing a stretch of single track.

Wayside signals are shown located at intervals along the way to governthe trailic. These signals may be of the well-known semaphore type or ofany of the well-known light signal types, but for the purpose of thisdisclosure search light type signals have been employed.

The signals R2, l0, l2 and R4 govern trafilc moving from left to right,and signals L4, [3, I l and L2 govern traffic moving from right to left.

The lamp circuits of the semi-automatic signals located at therespective ends of the stretch are not shown, as the lamps of thesesignals are assumed to be constantly lighted from a suitable currentsource. The lamps Ell], Ell, El2, and El 3 of the automatic signals 10to l3, respectively, located at intermediate points of the stretch areapproach lighted under control of approach lighting relays IBER, ER andI 2-l3ER.

Relays BJTR', iTR, AZTR, B2TR, IOTR, AIUTR, BIOTR, I2TR, AIZTR, 3TR, andA4TR are track relays controlled by their respective track circuits inthe usual manner.

Relays LZFR, lilFR, HFR, l2l3FR and FR are polarized trafiic relays thatgovern the direction of traflic by their respective signals. RelaysIDNFP, IORFP, IINFP, HRFP, I2I3NFP and l2--l3RFP are neutral repeaterrelays of the above-identified polarized traffic relays and are merelyemployed to obtain the required number of contacts without the necessityof overloading the polarized relays.

Relays RZH, LAZH, RAM-I and L4H are polarized home control relays usedto control their respective signals. The relays RAZI-IP, RB2I-l'P,LAZHP, RA4HP, LA4I-IP and LBAHP are slowreleasing repeating relays ofthe above polarized home control relays and are used to bridge thepole-changing period of such relays. The polechanging relays LA2PC,HlPC, IIPC, l2l3PC and RAdPC are slow-acting repeaters of theirrespective signals. Relays LBZH and RB4H are neutral home control relaysof their respective signals. The relays R2GP, L2GP, RAGP and L4GP arerepeaters of their respective signals in the stop position.

The relays LZMR, RZMR, L41VR and R4MR are locking relays with automatictrack circuit release and are also released, in emergency, by theassociated time element relays ZTE and 4TE.

The relays L2HS and RZHS are operator controlled relays governingtraflic over switch I S and the adjacent territory, while relays L4I-ISand RAHS are operator controlled relays governing traffic over switch 38and the adjacent territory. The operator may, for example, control theserelays by means of levers V2 and V3.

In the accompanying drawings the contacts of each relay, wheneverpossible, are shown directly under that relay, but in each instanceWhere this is impractical, the contact is labeled with its relaydesignation and with a numerical sufiix. Separate sources of current areemployed at the respective signal locations and for convenience thesehave been diagrammatically illustrated as comprising batteries DI and D5having their positive terminal identified by the letter B and theirnegative terminal identified by the letter C. i

It is believed the invention can best be described by explaining theoperations which are performed when the signals are to be cleared for atraffic movement. To clear the signals for a movement from left toright, the operator controlled relay L4HS must be in its releasedposition, all intervening track sections unoccupied with theirrespective track relays picked up, and the operator controlled relayR2HS energized. A circuit is then completed from a B terminal of thebattery D5 through back contact L4HSI; through the front contact LdMR!of locking relay LAMR, to check that the L4 signal has not been clearedand then returned to stop without giving an approaching train sufiicienttime to stop before entering the control stretch; the conductor H, thewinding of traffic relay l2--l3FR, conductor l2, through contactsbridged by arm ZSI of the circuit controller of switch 2S, conductor I3,the winding of traffic relay HJFR, conductor M, the locking relay frontcontact R2MRl, through the front contacts RZHSI and RZHSZ in series,conductor IS, the winding of traffic relay LZFR, front contacts l6 andI! of track relays TR and AZTR, conductor l8, front contact IQ of trackrelay BZTR, conductors 2i and 20a, front contact 2| of relay IOPC andconductor 22a to conductor 23, or, if traffic has been set up for theopposite direction, from conductors 243 and 2%, front contact 6| ofrelay 1 URFP and conductor 22?) to conductor 23, front contact 24 oftrack relay IGTR, contacts bridged by the switch circuit controller arm2S2, conductor 25, conductor 25a, front contact 26 of relay HN'FP toconductor 21a, or, if trafiic has been set up for the oppositedirection, over conductors 25 and 25b, front contact 28 of relay I I PC,conductors 21b and 27a, through the winding of traffic relay l IFR,front contact 29 of track relay AHiTR, conductor 30, front contact 3! oftrack relay BIDTR, front contact 32 of relay l2|3PC, front contact 33 ofrelay lZTR, conductor 34, front contacts 35 and 36 of track relaysAIZTR, and STR, respectively, the winding of traflic relay 4FR,conductor 31, and through the back contact L4HS2 to a C terminal of thebattery D5.

With current flow through all of the trafiic controlling relays in thedirection traced, they are energized in the normal direction to theleft, as illustrated in the accompanying drawings, With the trafficrelays in this position, and the operator controlled relay RZHS'energized, a circuit will be completed for clearing one of the R2signals, as will subsequently be described.

Since the signal RAG at the right end of the stretch is at stop, itsdistant signal I2 is held in its caution position. The circuit overwhich the signal I2 is held extends from a B terminal of battery D5through back contract 53 of relay RA lPC', normal polar contact 52 ofrelay 4FR, conductor 5!, front contact 55 of relay l2 l3NF'P, conductors49a and 49, through the normal polar contact d8 of relay l2--l3FR,conductor 41, the winding of the signal l2, conductor 45, normal polarcontact 45 of relay l2-l3FR, conductors M2 and 542a, front contact a ofrelay I2I3N'FP, front contact 43 of track relay IZTR, conductor 42,front contacts ll and .40 of track relays AHZTR and 3TR, respectively,the normal polar contact 39 of relayjFR and through the back contact 38of relay RA4PC to a C terminal of the battery D5,

On the other hand, if signal RA4 is in the clear or caution position,relay RA4PC is energized over a circuit extending from a B terminal ofthe battery D5 through R and G, or Y, contacts of the signal RA andthrough the winding of relay PtA iPC to a C terminal of the battery D5.With the relay RALiPC energized, it will be apparent that the circuittraced through the winding of signal I2 will be in the reverse directionand such signal will accordingly operate to its clear position. With thecircuits as illustrated it will be apparent that the relay I2l3NFP isenergized over a circuit including the normal polar contact 58 oftrafiic relay I2l3FR.

With signal l2 in either its clear or caution position, relay iZ-lSPC isenergized over a circuit extending from a B terminal of battery D4through G, or R and Y, contacts of signal 12, conductor 59, frontcontact 10 of relay IZI3NFP,

conductor H, conductor "Na, and through the winding of relay l2l3PC to aC terminal of the battery D4.

With traiiic set up as described above, signal it is held in its clearposition over a circuit extending from a B terminal of the battery D4through the R contacts of signal l3 closed in the stop position, andtherefore checking that the' ductor 84, back contact of relay IIRFP,conductor 88, front contact 81 of relay IONFP, conductor 88, the windingof signal ll), conductor 89, normal polar contact of relay IUFR, frontcontact S! of relay lflNFP, front contact 92 of track relay lS'IR,conductor 93, back contact 94 of relay 1 HRFP, front contact 95 of relayIINFP, front contact 95 of track relay AIBTR, conductor 91, frontcontact 98 of track relay BIOTR, back contact 99 of relay l2l3RFP,conductors 100a, lllil, and through the front contact IOI of relayl2l3PC to a C terminal of the battery'D4.

If signal I2 is at stop due to a train being in section I 2T or Al 2Tand with traflic set up as outlined above, the circuit traced throughrelay l2- IBPC will be interrupted at both the G and Y contacts ofsignal l2 and relay I2--I3PC will accordingly assume its releasedposition. With relay I2l3PC in the released position, current flowthrough the circuit traced to signal H] will be in the reverse directionto that traced and signal 10 will accordingly move from its clear to itscaution position.

With signal ID in either the clear or caution position, the associatedrelay lllPC is held energized and completes a circuit for operating thehome signal control relay RZH to its normal position. This circuitextends from a B terminal of battery ,D2 through the winding of approachlighting relay HlER, conductor I82, through front contact Hi3 of relayIDPC, conductor I04, back contact 95 of relay IURFP, conductor I06,normal polar contact ID! of relay LZFR, through the winding of relayRZH, conductor I08, normal polar contact MS of relay L2FR, frontcontacts I I0 and l l l of track relays HR and AZTR, conductor I I2,front contact I I3 of track relay B2TR, back contact N4 of relay HBRFP,conductor H5, and through the front contact I iii of relay IUPC to a Cterminal of the battery D2. If signal In is in the stop position, thecircuit of relay |0PC will be interrupted at the Y and G contacts ofsignal It! and the relay IDPC will accordingly be in the releaseposition and accordingly the current flow over the circuit traced to therelay RZH is in the direction for energizing it to its reverse position,opposite to the position in which it is shown.

With relays R2I-l and RBI-IS energized, and with switch is in its normalposition, an energizing circuit is completed for the repeating relayRAZHP. This circuit extends from a B terminal of the battery Dl throughfront contact 54 of track relay lTR, the back contact 2TEI of the timeelement relayZTE; front contact L2GPl, checking that the opposingsignals are at stop; front contact R2HS3 of the energized operatorcontrolled relay RZHS, front neutral contact 56 of relay RZH, circuitcontroller ISI in its normal position, and through the winding of relayRAEHP to a C terminal of the battery DI. If the switch is is in thereverse position, its circuit controller arm I Si will be in its reverseposition and accordingly relay RBZHP will be energized in lieu of RAZHP.

With relays R252 and RAZHP energized, a circuit is closed for energizingsignal RA2 effective to move it to a proceed position. This circuitextends from a B terminal of battery DI through the normal polar contactof relay R2H, the winding of signal RAZ, the normal polar contact 58 ofrelay RZH and through the front contact 59 of RAZHP to a C terminal ofthe battery DI. If relay R2I-I is energized in the normal direction asillustrated, the current supply to the winding of the signal RA2 is insuch direction that it will operate the signal to its clear position;but if relay RZH is in its reverse position, the current flow throughsignal RAZ will be in the opposite direction and the signal will beoperated to its caution position. If relays R2I-I and RB2HP areenergized, the signal RBZ, instead of signal RAZ, will be the one whichis operated to a proceed position. Since the signal RBZ is controlled byrelays REH and RBEHP in the same manner as signal RA2 by the relay R2Hand the relay RAEHP, the manner of operating RBZ to its clear or cautionposition will be apparent.

The energizing circuit of stop position signal repeating relay RZGPextends from a B terminal of the battery D! through the R contacts ofsignal RA? in series, conductor 6!], through the R contacts of signalRB; in series, and through the winding of relay RZGP to a C terminal ofthe battery Di. It will be apparent, therefore, that when either signalRA2 or BB2 is removed to a pr ceed position, the circuit of relay RZGPwill be interrupted. When the relay R2GP releases, its front contact 52opens the stick circuit of look ing relay REMR which, in turn, releases,and at its contact R2MRl opens the trafilc locking circuit, therebypreventing the position of the traffic relays being changed when signalRA2 or RBZ,

is in a proceed position. The pick-up circuit for relay REMR, if thesignal is operated to its stop position by a train entering the sectionover a which it governs, extends from a B terminal of the battery DI,through front contact 62 of relay RZGP, conductors 6S and 63a, backcontact AZTP-si of track relay A2'IR, through back contact Z'IZl of thetrack repeating'relay ITZ, con- E ductor 6 3, and through the winding ofrelay RQMR to a C terminal of the battery DI. If the signal is returnedto stop by the operator, the pick-up circuit extends over conductors 63and 63b through the front contact 2TE2 of the time element relay,conductors 64a and 64. The time element relay Z'I'E operates only whenthe signal has been returned to stop by the operator. The circuit of therelay ZTE extends from a B terminal of the battery DI, through frontcontact 62, conductors 63 and 630, back contact 65 of relay RZMR,conductors 66a and 61, front contact ITRI and through the winding ofrelay 2TE to a C terminal of the battery DI. The stick circuit for relayR2MR comprises the first portion of the operating circuit of relay 2TE,but includes the front contact 65 of relay RZMIR, instead of the backcontact.

Referring to Fig. 4, the leaving end of the stretch, the operator clearssignal R4 by picking up operator controlled relay R4HS. The polarizedhome control relay RA lH is energized through circuits controlled bysections extending to the right of the stretch. These circuits have nobearing on the invention and therefore have not been shown. Relay RAQHP,controlled in part by contact 16 of relay RA-tH, checks the trackcircuit through the section 3T at contact 12 of track relay 3TR, andchecks the normal position of switch 3S through the circuit controllercontact 3S2 of the switch 33, and, through being controlled by relayRAH, checks the track circuit of section A41 and others so as to preventopposing moves. Relay RA lHP is a slow releasing repeater of relay RAlH, While the relay RB lH is the home control relay for signal BB4. Thecontrolling circuits for these relays extend from a, B terminal of thebattery D5, through contact I2 of track relay 3TR, back contact QTEI oftime element relay 4TE, through the front contacts L4GPI and RAHSI;through the circuit controller arm 382 in its upper position, when theswitch 38 is in its normal position; the front neutral contact 2'6 ofrelay RAM-I, and through the winding of relay RAM-1P to a C terminal ofthe battery D5. If the switch 38 is in its reverse position, a circuitwill be completed through relay RBAH in lieu of relay RA IHP.

With relays RA lH and RAtHP energized, a circuit is completed for movingthe signal RAG to a proceed position. For example, if the polar homecontrol relay RA tI-I is energized in the normal direction, its polarcontacts will be in the position shown and the circuit completed throughthe winding of signal RA i will be in such direction that it will beoperated to its clear position. If the relay RA4H at the time has itspolar con tacts in their reverse positions, the current flow through thewinding of the signal will be in the reverse direction and it willaccordingly move to its caution position. With the relay RB iI-Ienergized, the signal R34 is operated to its caution position over theobvious circuit completed through the front contact of relay RBGH.

With signal RA l in either the clear or caution position, the relayRAQPC is energized. The circuit for this relay extends from a B terminalof the battery D5 through the R and G or Y contacts of signal RIM andthrough the winding of relay RA4PC, to a C terminal of the battery D5.The relay R lGP is normally energized over a circuit extending from a Bterminal of the battery D5 through the R or stop position contacts ofsignals RAG and R134 in series. Therefore, if either signal RAd or BB4is moved to a proceed position, the relay RQGP becomes deenergized. Thecontrol and operation of locking relay RAMPu by relay RAGP and by theoperator is similar to that described for locking relay RZMR and adescription of these operations is therefore believed to be unnecessary.

The operations required to set up tramc from right to left over thestretch by clearing signals L4 and L2 and the control of these signalsis similar to that described for signals R2 and R4. The circuits andapparatus at the respective ends of the stretch and comprising Fig. 1and Fig. 4, respectively, are identical, and therefore in describing theestablishment of trafiic from right to left, circuit changes occurringat these locations in the stretch will be readily understood. In orderto establish traffic from right to left, the opposite direction to thatdescribed, the operator controlled relay RZHS must be deenergized, allintervening track sections clear, and the operator controlled relay L4HSenergized. A circuit will then be completed over the traflic circuitfrom the current source DI through the back contacts R2HSI and R2HS2instead of from source D through back contacts L4I-ISI and L4HS2; andsince the battery DI is connected to the trafiic circuit in opposedrelation to the connection of battery D5, the current flow through thetrafiic circuit will be in the reverse direction to that formerlytraced. The traffic relays when energized will accordingly move theirpolar contacts to the reverse position, opposite to that shown. Since,as previously stated, the equipment of Fig. 1 and Fig. 4 is alike, thechanges occurring at these locations as a result of the operation oftraffic relays LZFR and 4FR to their reverse positions will be readilyunderstood.

At the location of signal III, the traffic relay IIIFR, at its polarcontact 90, opens a point in the circuit formerly traced through theWinding of signal III, which accordingly moves to its stop position, andat its polar contact I21 opens a point in the circuit to the lamp EIIIof this signal. The relay IIlFR. also, at its polar contacts I26, opensthe circuit of relay IIINFP and closes the circuit of relay IBRFP.

At the location of signal II, traflic relay I IFR, at its polar contactI28, closes a point in the energizing circuit of signal I I and atcontact I29 closes a point in the circuit of the lamp EII of thissignal. The relay III' R also, at its contacts I39, opens the circuit ofrelay IINFP and completes a circuit through the relay II RFP.

At the location of signals I2 and I3, the trafiic relay I2-I3FR, at itspolar contacts 45 and 49, opens points in the circuit formerly tracedthrough the winding of signal I2, which then moves to its stop position,and then closes points in the circuit including the winding of signalI3. The relay I2-I3FR also, at polar contact I4, transfers theconnection of the winding of approach lighting relay I2I3ER fromconductor I3, heretofore connected to a B terminal of the battery D4through R contacts of signal I3 to conductor I3I, now connected to a Bterminal of battery D4, via the R contacts of signal I2, now in its stopposition.

With the relays IURFP, IIRFP and I2-I3RFP energized, and relays IONFP,IINFP and I2I3NFP deenergized, and the signal LA2 in its stop position,circuits are completed for moving signals I I and I3 to caution andproceed positions, respectively. The circuit for signal II extends froma B terminal of battery DI through back contact I38 of relay LA2PC,reverse polar contact I 91 of relay L2FR, conductor I96, front contactI95 of relay IIIRFP, back contact 8'! of relay IORFP, back contact 81 ofrelay IIINFP, conductor 86, front contact 85 of relay IIRFP, conductorI3'I, through the winding of signal II, conductor I38, reverse polarcontact I28 of relay IIFR, front contact 94 of relay IIRFP, conductor93, front contact 92 of track relay IDTR, back contact SI of relayIBNFP, conductor I35, back contact I34 of relay IIIPC, conductor I33,front contact II4 of relay I ORFP, front contact II3 of track relayBZTR, conductor II2, front contact III of track relay AZTR, and III] oftrack relay ITR, reverse polar contact I09 of relay LZFR, and throughthe back contact I32 of relay LA2PC to a C terminal of the battery DI.With current flow through the winding of signal II in the directiontraced, the signal I I is moved to its caution position. With the signalII in its caution position, an operating circuit is completed for thepolechanging relay II PC. This circuit extends from a B terminal of thebattery D3, through R and Y contacts of the signal I I and through theWinding of relay IIPC to a C terminal of the battery D3.

With relay IIPC picked up, the circuit completed through the winding ofthe signal I3 extends from a B terminal of battery D3, through thewinding of approach lighting relay IIER, conductor I 39, front contactI40 of relay IIPC, conductor I4I, through the back contact 8I of relayIINFP, conductor 89, front contact I9 of relay I2-I3RFP, conductors 49band 49, reverse polar contact 48, through the winding of signal I3. thereverse polar contact 45, conductors I42 and M21), through front contact99 of relay I2I3RFP, front contact 98 of track relay BIOTR, conductor91, front contact 96 of track relay AIUTR, back contact 95 of relayIINFP, conductor I43, and through the front contact I44 of relay II PCto a C terminal of the battery D3. It will be readily understood that toclear signal L2 the operator must pick up operator controlled relayL2I-IS and that the operations which follow will correspond to thosewhich followed the picking up of relay R4HS to clear signal R4.

It will be observed that the controlling circuit of signals RA2 and BB2includes front contact L2GPI of the stop position repeating relay LZGP,thereby checking that the LA2 and LB2 signals are both at stop when oneof the R2 signals is being cleared. In a similar manner, the contactsRZGPI of relay RZGP check that signals HA2 and BB2 are in their stopposition when one of the L2 signals is cleared. It will be apparent thatthe same protection is provided for opposing signals located at theopposite end of the stretch.

It will also be observed that at the double intermediate signallocation, before signal I2 or I3 can be moved to a proceed indicatingposition,

trafiic relay I2I3FR will interrupt the operating circuit of theopposing signal at such location; also at the one single intermediatesignal location the trafiic relay I I FR must be in its normal positionand have opened the circuit to the winding and lamp of signal II and, inaddition, traflic relay IIIFR. must be in its normal position before acircuit can be completed for moving signal III to a proceed position.Similarly, both trafii'c relays IIIFR and IIFR, must be in their reverseposition before a circuit can be completed through the winding of signalI I.

In the preceding description the operations required to clear thesignals for movement of traffic through the stretch in either directionwere described without regard to any influence the circuit controllersof switch 28 at an intermediate point in the stretch might have. Thecircuit controller of switch 28 is employed to control the trafficcircuit in such manner that when the switch 2S is moved to the reverseposition, traflic will automatically be set up in opposite directionsfrom this switch location.

If, for example, trafiic has been set up for a train movement into thestretch from the right end thereof, and the train entering the stretchis to pick up or leave cars on the siding P2, the operator will releasethe operator controlled relay L4HS after the train has entered thestretch. This does not alter the trafiic set up because the polar relaysin the traffic circuit retain their armatures in their last operatedposition and the dropping of relay L4I-IS is merely effective toreconnect battery D5 in bridge of the right-hand end of the trafiiccircuit in opposition to that already connected to the left-hand end ofthe circuit. Since no current flows over the circuit under thiscondition, the polar armatures of the trafiic relays remain in theirlast operated position.

When the train arrives at switch 28 and this switch is moved to itsreverse position, the circuit controller arms 25! and 282 first separatethe left and right-hand portions of the traflic circuit from each otherand then bridge the respective halves of the circuit with resistors RIand R2, so that the left-half of the traffic circuit is now included ina circuit now open at contacts 24 of track relay IBTR, including batteryDI, while the right half is included in a closed circuit including thebattery D5. It will be observed that if the train enters the siding P2and clear of track section I T, the circuit through the left-hand end ofthe traffic circuit will also be completed, and that in such case thedirection of current flow will be the same as when relay L4HS is pickedup to set up trafiic from right to left through the stretch. Therefore,the polar contacts of traific relays LZFR and IOFR will remain in theiroriginal position as required for traffic movements from right to left.In the case of the right-hand portion of the trafiic circuit, however,the current flow will be in the opposite direction to that originally.set up, and accordingly the traific relays HFR, l2-I3FR and 4FR willmove their polar armatures to the opposite position and will accordinglyprepare their associated signal circuits for traific movements from leftto right. After the necessary switching operations have been performedand the train recedes from the switch back onto the main line, theswitch 28 is restored to its normal position and its circuit controllerarms 28! and 282 reconnect the two halves of the circuit together. Sincethe batteries at opposite ends of the traffic circuit are in opposingrelation, there will be no resultant current flow over the circuit and,therefore, the polarized traffic relays will not change the position oftheir polar contacts at this time. The operator may now clear signal L2to direct the train movement on through the stretch or, if he desires,be may clear signal R4 to enable the train to recede out of the stretchunder full signal protection.

In a similar manner, if the signals are cleared for movement of a traininto the stretch from the left end, the switch 2S may be reversed afterthe train has passed it, and if the operator has previously releasedrelay RZHS, current will flow through the right-hand section of thetrafiic circuit as soon asthe switch 2S has been reversed in the samedirection as when signal R2 is cleared, and accordingly the signalsremain set for the direction of trafiic from left to right from theswitch location. When the train clears section I 0T, either by enteringthe siding or by moving on into section AHJT, the track relay HITR willcomplete the circuit through the left-hand portion of the trafficcircuit; and since current supplied to it is from battery Dl instead ofD5, the direction of current flow is reverse to that originally set up.The traflic relays LZFR, and NPR, accordingly move their polar armaturesto the opposite position, as required in the preparation for trafficmovements from right to left. The operator may therefore now direct themovement of the train out of the stretch in either direction.

Under either of the foregoing examples, it will be readily apparent thatwhen the train leaves the stretch the polarized relays included in theleft portion of the trafilc circuit will have their armatures in theopposite position to the armatures of the trafiic relays included in theright-hand portion of the traflic circuit. As soon, however, as theoperator picks up relay RZHS or HHS to establish trafiic in a givendirection, all of the polarized relays in the trafiic circuit will beenergized by current flow in the same direction to again establishtraffic through the stretch in the direction depending on which of theoperator controlled relays has been picked up.

It will be appreciated from the foregoing that the apparatus andcircuits herein employed are so arranged that the unoccupied conditionof all sections of the stretch and the stop position of all opposingsignals are checked before traffic can be set up through the stretch;also, that once the direction of traffic has been established, sincepolarized relays which retain their armatures in their last operatedposition are employed, is free from the danger of .a loss of trafficdirection. Furthermore, that a novel arrangement has been providedenabling the train to reverse its direction of travel at an intermediatepoint in the stretch and that full signal protection is provided forsuch movement.

Although I have herein. shown and described only one form of apparatusembodying my invention, it is to be understood that various changes .andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track over which trafficnormally moves in either direction, a normally deenergized directionalcircuit for the stretch including a directional relay at each end of thestretch and the outgoing and return conductors of which are normallydisconnected from each other, a source of current at each end of thestretch normally connected to said circuit, a home signal control relayat each end of the stretch, operator controlled means to selectivelydisconnect one or the other of said sources of current from said circuitand for connecting the conductors of said circuit together to render theother source at the opposite end active to energize said circuit, andcontacts on the directional relay at the end of the circuit from whichthe source of current has been disconnected to prepare an operatingcircuit for said home signal relay at its end.

2. A railway signal system for a stretch of railway, a first set ofsignals located at intervals to govern traffic in one direction throughthe stretch, a second set of signals located at intervals to governtraffic in the opposite direction through the stretch, a track circuitfor each signal responsive to trafiic conditions in advance of thesignal, manually controlled means to establish the direction of trafficto cooperate with the track circuits to selectively clear one or theother of said sets of signals; a railway track switch associated withthe stretch of railway located at an intermediate point in the stretchhaving a normal position for directing tramc movements along saidstretch and having a reverse position for directing traffic movements toor from said stretch; and means controlled by said track switch in itsreverse position for clearing signals of one of said sets for governingtraffic movements in the corresponding direction away from said switchwhile signals of the other set are clear for governing traffic movementsin the opposite direction away from said switch.

3. A railway signal system for a stretch of railway, a first set ofsignals located at intervals to govern trafiic in one direction throughthe stretch, a second set of signals located at intervals to governtrafiic in the opposite direction through the stretch, a control circuitfor each signal responsive to traffic conditions in advance of thesignal, a manually controlled directional means cooperative with thecontrol circuits to selectively clear one or the other of said sets ofsignals, and means at an intermediate point in the stretch operable tocooperate with said manually controlled directionalmeans for clearingsignals of one of said sets to the rear of a train occupying suchintermediate point to enable such train to recede out of the stretchunder full signal protection.

4. A railway signal system for a stretch of railway, a first set ofsignals located at intervals to govern trafiic in one direction throughthe stretch, a second set of signals located at intervals to governtraflic in the opposite direction through the stretch, a control circuitfor each signal responsive to traffic conditions in advance of thesignal, manually controlled directional means adapted to cooperate withthe control circuits to selectively clear one or the other of said setsof signals, and means at an intermediate point in the stretch operableto cooperate with said manually controlled directional means while thereis a train occupying said stretch at such point to clear signals in therear of the train for directing traffic movement in the directionopposite that under which the train entered the stretch.

5. A railway signal system for a stretch of railway, a first set ofsignals located at intervals to govern traffic in one direction throughthe stretch, a second set of signals located at intervals to governtrafiic in the opposite direction through the stretch, a control circuitfor each signal responsive to traffiic conditions in advance of thesignal, manually controlled directional means adapted to cooperate withthe control circuits to selectively clear one or the other set ofsignals; and a device cooperating with said manually controlleddirectional means for clearing signals of one set in the rear of a trainat an intermediate point in said stretch while said manually controlleddirectional means is in condition for clearing signals of the other setin advance of the train.

6. In combination, a stretch of railway over which trafiic normallymoves in either direction, a directional circuit for the stretchextending between the ends thereof and including a source of current ateach end of the stretch normally connected in said circuit in opposedrelation to the corresponding current source at the opposite end, .abridge at each end of the stretch, operator controlled means toselectively disconnect one or the other of said current sources fromsaid circuit and for temporarily substituting the associated bridgetherefor to render the source of current located at the end oppositethat of the selected bridge active to energize said circuit, polarizedrelays included in said circuit and operated to set up traffic throughsaid stretch in a direction depending on the source of current fromwhich said relays have been energized, and means for separating thecircuit at an intermedi ate point in the stretch and for then bridgingthe separated portions at such point to prepare the respective portionsfor energization from the connected current sources to operate thepolarized relays in the respective portions of the original circuit toset up traflic in opposite directions from such intermediate point.

'7. In combination with a stretch of railway, a normally closeddirectional trafilc circuit extending between the ends of the stretchand irrcluding in series polarized signal control relays at respectivesignal locations along the stretch, a. source of current at one end ofthe stretch included in said circuit, a second source of current at theother end of the stretch also included in said circuit but connected inopposing relation to said first current source so that no currentnormally flows through said circuit, means for removing one or the otherof said current sources from said circuit and for directly connectingthe conductors together at such point to enable the circuit and therelays therein to be energized by current flow in a direction dependingon the source of current remaining connected in said circuit to enablesaid relays to selectively determine the direction in which traific isto be set up through the stretch, and means for enabling differentportions of said circuit to be energized from the connected currentsources so that the relays of one portion will become energized bycurrent flow in the opposite direction to that last flowing through suchrelays to enable the establishment of trafiic in the portion of thestretch served by such portion of the traflic circuit in the oppositedirection to that last established through the entire stretch.

8. In combination, a stretch of railway over which trafiic normallymoves in either direction, a directional circuit for the stretch, asource of current at each end of the stretch normally con nected to saiddirectional circuit in opposing relation to each other so that normallythere is no current flow over the circuit, a directional relay at eachend of the stretch, an operator controlled means at each end of thestretch each adapted when energized to disconnect the source of currentat its end of the stretch from the directional circuit and to substitutetherefor a direct current bridge to enable the energization of theassociated and distant relay in one direction by current supplied at theopposite end of the stretch in the direction required to enable theestablishment of traflic in a given direction through the stretchdepending on the current source employed in the energization of saidrelays, and means for separating the respective ends of the circuit andfor closing together such separated ends to efiect energization of eachdi rectional relay from the associated current source to operate them inopposite directions to establish opposite directions of traffic throughthe stretch from the point of separation of the circuit.

9. In combination, a stretch of railway over which trafiic normallymoves in both directions, a first set of signals located at intervals togovern the passage of trains through the stretch in one direction, asecond set of signals located at intervals to govern the passage oftrains through the stretch in the opposite direction; operatorcontrolled means, including a series of polarized directional relaysselectively energized in one direction or the other for selectivelyclearing either the first or the second set of signals to direct themovement of a train through the stretch, means controlled by a train asit passes signals of the set cleared to cause their return to stop, andmeans at an intermediate point in the stretch which can be operated toenable a selected portion of said relays to be energized in the properdirection to enable an operator to clear opposing signals passed by atrain entering the stretch to direct the movement of a train recedingout of the stretch.

10. In combination, a stretch of railway over which traffic normallymoves in both directions, a first set of signals located at intervals togovern the passage of trains-through the stretch in one direction, asecond set of signals located at intervals to govern the passage oftrains through the stretch in the opposite direction; operatorcontrolled means, including a series of polarized directional relaysselectively energized in one direction or the other for selectivelyclearing either the first or the second set of signals to direct themovement of a train through the stretch, means controlled by a train asit passes signals of the set cleared to cause their return to stop, andmeans at an intermediate point in the stretch which can be operated toenable a selected portion of said relays to be energized in the properdirection to enable an operator to clear opposing signals passed by atrain entering the stretch to direct the movement of a train recedingout of the stretch irrespective of the end of the stretch via which itentered.

11. In a signaling system wherein a group of polarized relays of thetype which retain their polar contacts in their last operated positionare energized by current passed through all of them in one direction orthe other to set up trafiic in one direction or the other, the provisionof means enabling a circuit to be completed through a portion of suchrelays with the current fiow in the reverse direction to that lastpassing through all of the relays toreverse the position of theircontacts with respect to the position of the contacts of the polarizedrelays not included in such portion and accordingly the direction oftraffic only over that portion of the stretch over which they exercisecontrol.

12. In combination, a circuit including two polarized trafi'ic governingrelays respectively associated with the'opposite ends of a stretch ofrailway track over which trafiic is to move in either direction, acurrent source at each end of the circuit normally connected thereto forsupplying current to said circuit, a remotely controlled relayassociated with each end of the circuit, means governed by each relaywhen energized to exclude the associated current source from saidcircuit to enable the traflic governing relays therein to be energizedfrom the source at the opposite end of the circuit, signals governed bythe trafiic governing relays to permit traflic to move through thestretch in a direction determined by the end at which said circuit issupplied with current, and means at an intermediate point of the stretchoperable to enable the reconnection of the disconnected source to thecircuit to be effective to energize the trafiic relay at its end topermit trafiic to move from such intermediate point out of the stretchin either direction.

13. In combination, a stretch of railway track, a plurality of signalsspaced along said stretch for governing trafiic movements in a givendirection over said stretch, other signals spaced along said stretch forgoverning trafiic movements in the opposite direction over said stretch,a trafiic direction circuit, a contact at each signal location includedin said trafiic direction circuit and controlled by a signal at the samesignal location and arranged to be closed only when that signal isdirecting a train to proceed, means for energizing said trafficdirection circuit by current of either polarity, means controlled bysaid traific direction circuit when energized by current of a givenpolarity for clearing said plurality of signals, and means controlled bysaid traffic direction circuit when energized by current of the oppositepolarity for clearing said other signals.

14. In combination, a stretch of railway track, a signal located at agiven point for governing traffic movements in a given direction on saidstretch, a second signal located at a second point for governing trafficmovements in the opposite direction on said stretch, a traffic directioncircuit, means for energizing said traffic direction circuit by currentof either polarity, means controlled by said trafiic direction circuitwhen energized by current of a given polarity for clearing said firstsignal, means controlled by said traflic direction circuit whenenergized by current of the opposite polarity for clearing said secondsignal, a contact in said trafiic direction circuit closed by saidtrafilc direction circuit upon becoming energized by current of saidgiven polarity, a second contact in said traffic direction circuitclosed by said trafiic direction circuit upon becoming energized bycurrent of said opposite polarity, a third contact in multiple with saidsecond contact closed by said first signal while directing a train toproceed, and a fourth contact in multiple with said first contact closedby said second signal while directing a train to proceed.

15. In combination, a stretch of railway track, a signal located at agiven point for governing trafiic movements in a given direction on saidstretch, a second signal located at a second point for governing trafficmovements in the opposite direction on said stretch, a trafiic directioncircuit including a first and a second polarized control relay for saidfirst and second signals respectively, means for energizing said traificdirection circuit by current of either polarity, a neutral relayenergized by a circuit including a normal contact closed by said firstpolarized relay when energized by current of a given polarity, a secondneutral relay energized by a circuit including a reverse contact closedby said second polarized relay when energized by current of the oppositepolarity, means controlled by a normal contact of said first polarizedrelay and by a front contact of said first neutral relay and also by aback contact of said second neutral relay for clearing said firstsignal, and means controlled by a reverse contact of said secondpolarized relay and by a front contact of said second neutral relay andalso by a back contact of said first neutral relay for clearing saidsecond signal.

16. In combination, a stretch of railway track, a signal located at agiven point having a lamp cooperating with a mechanism operable to astop position and also to a second position for directing trafiicmovements in a given direction on said stretch, a second signal locatedat a second point having a lamp cooperating with a mechanism operable toa stop position and also to a second position for directing trafficmovements in the opposite direction on said stretch, a traiiic directioncircuit, means for energizing said traflic direction circuit by currentof either polarity, means controlled by said trafiic direction circuitwhen energized by current of a given polarity for operating themechanism of said first signal to its second position and also forlighting the lamp of said first signal when a train approaches saidsignal, and means controlled by said trafiic direction circuit whenenergized by current of the opposite polarity for operating themechanism of said second signal to its second position and also forlighting the lamp of said second signal when 10 a train approaches saidsecond signal.

PAUL P. STOKER.

